DD205342A1 - METHOD AND DEVICE FOR OPERATING ELECTRICALLY SEPARATORS - Google Patents

Abstract

The invention relates to a method and apparatus for energy-saving operation of electrostatic precipitators, electric separators and similar, for the separation of particles or droplets from gases electrical fields using facilities. The aim of the invention is to find a method and an apparatus for implementing the method, according to which the power consumption for the operation of electric precipitators is reduced in normal operating conditions and in critical operating cases, the technical complexity can be reduced, the technical complexity of the device also should be low. The invention has for its object to develop a method and a device that make it possible to realize an application-related adjustment of the optimal electrical parameters with simple, even in already existing circuits nachbeglich installable electrical equipment. According to the invention, this object is achieved in that the current supplied to the separator is provided on the primary side of the high voltage generator in pulses, wherein the voltage can have an arbitrary time course. The current pulses are adjustable in frequency and / or frequency and in their amplitude.

Description

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Title of the invention

Method and apparatus for operating Elektroabac heidern.

Field of application of the invention

The invention relates to a method and apparatus for energy-saving operation of electrostatic precipitators ^ Elektroaeparatoren and similar, for the separation of particles or droplets from gases electric fields using facilities.

Characteristic of the known technical solutions

For the separation of, for example, dusts from gases known electrical separators are used in which the dust particles are electrically charged and then the charged particles are moved in the electric field to a collecting electrode · To generate the required electric field high voltage generators are used, which are preferably equipped with self-rectifiers or silicon rectifiers are to generate the required DC voltage. Transducers or thyristors are mainly used for controlling and regulating the high voltage.

The object of this so equipped high voltage generator is to deliver a controllable high-voltage, mainly negative DC voltage, for example, in the electrostatic precipitator allows the structure of the electric field, which is necessary for the formation of charge carriers and dust transport. In this case, different voltage forms for the operation of the Elektroabscheider ^ usual.

A smooth as possible DC output voltage is sought by using three-phase current to the mains supply of the high voltage generator. When single-phase current is supplied, a pulsating DC voltage is generated. For special operating cases, in particular for the separation of high electrical resistivity dusts,

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Scheider Bücksprühen produce special voltage forms are used. These voltages should contain strong pulsating and partly reversed polar components. H. J. WHITE (H.J. WHITE j dedusting of industrial gases with electrostatic precipitators - VEB German publishing house for primary industry 1969, page 268 ff) describes, for example, a pulse generator that generates voltage pulses of 60 Hz and associated current pulses of 0.1 ms duration.

When using thyristors as a controlling element voltage pulses are given according to the mains frequency, followed by the analog current pulses. In the Federal Republic of Germany No. 2 253 601 a method is described in which the voltage is briefly kept above the corona operating voltage and then adjusted for a comparatively long time below the corona operating voltage in order to control the discharge current through the pulse frequency.

The aforementioned technical solutions have in common that the function of the downstream apparatus, in particular electrostatic precipitator, is influenced by the shape and the time course of the voltage. However, the current flow resulting from the respective voltage curve is the quantity which decisively influences the dust separation. There are very different and unpredictable relationships between the resulting current flow and the predetermined voltage shape, which are significantly affected by the instantaneous capacity of the downstream apparatus, such as an electrostatic precipitator, by pulse transmission in the high voltage transformer, by additional inductance and capacitance in the control circuit and more.

Disadvantage of this solution is that the operation of electrostatic precipitators by suitable adjustment of the electrical conditions (voltage level, voltage shape, average current) is not or in critical cases, for example, in dusts with high electrical resistivity, only with considerable technical effort can be influenced, in turn In normal operating conditions, a high energy intake results.

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Object of the invention

The aim of the invention is to find a method and an apparatus for implementing the method, according to which the power consumption for the operation of electric precipitators is reduced in normal operating conditions and in critical operating cases, the technical complexity can be reduced, the technical complexity of the device also should be low.

Explanation of the essence of the invention

The invention has for its object to develop a method and apparatus that makes it possible to realize an application-related adjustment of the optimal electrical parameters with simple, even in already existing circuits retrofittable electrical equipment.

According to the invention this object is achieved in that the current supplied to the separator on the primary side of the high voltage generator is provided in pulses, wherein the voltage can have any desired time course. The current pulses are adjustable in frequency and / or frequency and in their amplitude.

This behavior is achieved by the thyristors located in the primary circuit are controlled by an adjustable synchronous clock only to a portion of the possible half-waves of the primary voltage, wherein the control takes place in a known manner, and / or that arranged on the primary side of the high voltage generator current limiting reactor continuously decreases becomes.

embodiment

The invention will be explained in more detail below with reference to an example.

The accompanying drawings show:

Pig · 1: the scheme of a single-phase thyristor system with clocked control pulses for the thyristor and variation

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the inductance of the current limiting delta 2a.i the impulses of the mains voltage 5

Fig. 2bV: the netzaynchrone pulse sequence of the drive current for the thyristors j

Fig. 2c: the clocked te pulse train of Ansteuerstromea for the thyristors after the sequence positive = 4n + 1

negative = 4n + 2}

Fig. 2d .: the clocked pulse train of the drive current for the thyristors after the sequence positive = 6n + 1

negative = 6n + 4;

Fig. 2e .: the ge takte te pulse train of Ansteueratromea for the thyristors after the sequence positive = 1On +1

negative = 1On + 6 $

Fig. 2f: the clocked.e pulse sequence of the Ansteueratromea for the thyristors after the sequence poaitiv = 14-n + 1 • negative = 14-n + 8;

Fig., 35ί the pulse sequence by changing the inductance of the current limiting adrosa.

In Fig. 1, the scheme of influencing the current is shown. The thyristors 1 are controlled in the usual way via a synchronizer 2 by a Zündimpulsauterung 3, but arranged between ignition pulse control 5 u.öd thyristors 1 in the ignition 4 a equipped with a tap changer 5 clock 6 and the inductance between the thyristor 1 and high voltage generator 7 installi ^ rten current limiting reactor 8 is continuously variable by means of changeover switch 9. On the secondary side of the rectifier 10 and the consumer 11, preferably electrostatic precipitator connected to the high voltage generator 7 in a known manner.

In Fig. 2, some of the possible forms of the output current are shown. The diagram shows a) the shape of the specified mains voltage and the diagram b) the current diagram with normal untacted control. The in the diagrams c) to

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f) pulse trains occur when the sequence of locked ignition pulses at both thyristors 1 = 2n + 2 and thus the distance of the current pulses is stretched. In Fig. 3, the pulse train is shown with changed inductance of the current limiting inductor 8 by continuously reducing the same.

At the arranged in the ignition 4 between Zündimpulssteuerung 3 and thyristor 1 clock 6, the intended mode is set by means of the tap changer 5, so that the thyristors 1 are controlled only according to the predetermined by the clock 6 mode.

The changeable by means of switch 9 inductance of the current limiting inductor 8 influences the driving angle of the thyristors 1 such that the votes in the secondary circuit of the high voltage generator 7 pulses of the rectified high voltage in pulse height and width can be varied.

These two possibilities can be used together as well as individually.

In both ways the power supplied to the high voltage generator is affected by the ripple of the current, which in the secondary circuit via the rectifier 10 the consumer 11, preferably an electric precipitator, supplied current in the same way. In contrast, the voltage present in the secondary circuit due to the capacitive effect of the consumer 11 is less wavy.

In this way, with constant amplitude of the current pulses of the average current value decreases. However, the stretching of the pulse intervals is only possible as far as the consumer 11 no'Beeinträchtigung the performance occurs.

Claims (2)

- * - 239673 4 Invention Claims 1. A method for the operation of Elektroabscheider ^, electrical separators and similar, for the separation of particles or droplets from gases electric fields utilizing devices in which controlled with thyristors high voltage generators are used, characterized in that the current generated for the operation of these consumers is pulsed on the primary side , wherein the current pulses are variable in pulse train, in pulse width and in pulse height and can be changed continuously or in stages, but the frequency of the current pulses is less than or equal to the mains frequency and that the fed voltage can have any course and / or that by variable or defines adjustable inductances between the thyristor and high voltage generator, the ripple of the consumer supplied output DC current in the secondary circuit of the high voltage generator increases with increasing modulation of the thyristor and / or with increasing peak value of the S. tromes decreases the pulse train. 2. Device for operating electrostatic precipitators, electric separators and the like, for the separation of particles or droplets from gases electric fields using devices in which controlled with thyristors high voltage generator are used, characterized in that for changing the pulse train of the current, for example by means of a tap changer ( 5) controllable clock (6) between the ignition pulse control (3) and thyristor (1) is arranged or connected directly to the ignition pulse control (3) and / or that to change the height and width of the current pulses via a changeover switch (9) variable current limiting reactor ( 8) or designed as a system of a plurality of fixed, reversible or one with a defined inductance current limiting inductor (8) and arranged between the thyristor (1) and high voltage generator (7). For this purpose__2._Se! Th drawings